In general, a carbon electrode is used as cathode of the lithium ion battery. The carbon electrode has an advantage that charging and discharging efficiencies of batteries are excellent. However, because of the low theoretical capacity of 375 mAh/g, it is limited to use as a cathode material for next-generation lithium ion batteries, which require a high battery capacity.
For example, in the case of silicon (Si) used as a cathode material for a lithium ion battery, it has a high theoretical capacity of about 4200 mAh/g. When the lithium ion battery is charged, high volume expansion up to 400% is caused because Li4.4 and Si reacts to form Li4.4Si. Such a high volume expansion causes a crack or a short to the cathode of a lithium ion battery consisting of a silicon material.
In particular, in the case of silicon (Si), when its particle size changes from micro size (μm) to nano size (nm), it is known that the stress caused by the volume expansion is reduced. However, the nano-sized silicon also has a problem that the crack or the short of batteries occur by the volume expansion.
Related Prior Art is the Republic of Korea Patent Publication No. 10-2003-0032763 (Apr. 26, 2003 published), where a nanoparticle manufacturing apparatus and a nanoparticle manufacturing method using the apparatus are disclosed.